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6.5 main bearing girdle

Discussion in 'GM 6.5 Diesel Engines' started by tightgroup, Dec 28, 2010.

  1. tightgroup

    tightgroup New Member

    Dec 24, 2010
  2. ak diesel driver

    ak diesel driver 6.5 driver

    Feb 7, 2009
    I think it's a waste of money. Too flimsy to do any real good. my .02
  3. X2 ^^ A waste of money. The only girdle that would be worth buying is one that is made of cast iron, same expansion rate as block, and 2nd it must tie the entire perimeter of the block and all the main caps together, to keep the main caps from shifting. Look at a P400 engine, that is essentially what it has to strengthen the bottom end as well as other mods.
  4. schiker

    schiker Well-Known Member

    Nov 9, 2008
    Pendleton, SC
    I dunno DSG is a respectable vendor. I wonder if its just the studs that help more than just the rails???? The thread repair inserts seem to work and the difference in between good 6.5's and cracked 6.5's is not clearly defined. Will the kit keep a block from cracking I doubt it. Will it help probably some. How much is the question and I don't think we can answer that it depends on the overall application. Worth the money ???? Depends on how much you have to spare. I'd like one for piece of mind but is it more than that ....not definatively proven.

    You can't really say with a 6.5 block if it hasn't cracked it probably won't. You can kinda sorta but not like a seasoned muscle car block. The cracks to me seem to be a cummalitive stress fatigue issue (or from direct abuse). Don't run them hot or abuse the bottom end with bad imbalance of injection/ timing issues and it seems to do ok.
  5. GM Guy

    GM Guy Manual Trans. 2WD Enthusiast

    May 6, 2008
    NW Kansas and SC Idaho
    Id waste money on it. but I am paranoid, and uneducated.

    hows that for an answer? :D

    but seriously, Ive seen bigger wastes of money. My personal take: It wont provide much strength, but IMHO, better than nothing at all.
  6. Missy Good Wench

    Missy Good Wench Wild Blonde from Cloud Mt

    Nov 19, 2008
    Newberg Oregon
    I have been into a buttload of these engines and still am not sure what makes them crack.

    I have seen engines that were run with the utmost care and love and they cracked all to hell.

    I have seen others that had the crap ran out of them and were totally crack free inside.

    The lock and stitch inserts done on all 6 of the center main outer holes is a great addition to any rebuild, even if the block is not cracked, I still do it.

    The little steel angle pieces are more of a warm fuzzy feel good thing.

    Adding the studs and locktiting them into the block before tightening the nuts likely takes a lot of the stress off the threads in the area of the outer mains and the little bars are probably doing NOTHING.

    The P400 is a helluva engine. That totally girdled lower end along with the forged crank is a real piece of work.

    A good block, even one thats been inserted along with a fresh scat crank and a ballance job will make a really good engine.

    Just my thoughts.

  7. jmiller

    jmiller Recruit

    May 6, 2008
    Lake Villa, CRIL
    I suppose the value of this type of "upgrade" is in it's construction. DSG is not the only vendor to offer this type of main cap stiffener. If the stiffener has appropriate thickness, hardness and stiffening features, it might do some good by tying the caps together. Otherwise the stiffener will just flex. Worse yet, just transfer the movement to the other center mains, damaging them all!

    Not being a mechanical engineer, just mechanically inclined, I can't say one way or the other.

    Before I dropped almost $300, I would talk to machine shops that have used it and are willing to stand behind it. I would also look for things that show it has strength, material, thickness, embossments, rolled edges, etc. If its stamped cold rolled sheet steel, run.

    Personally, for this type of design, a tie in to the rear main would make more sense from a strength perspective. The cast girdle that ties into whole block perimeter and all five caps is the better design. (but comes with that specific block design)

    Just my view of it.
  8. Being a big block buick guy I have an unfortunate amount of knowledge of block girdles and lack of H/G sealing that those engines are plagued with, also poor oiling system, come to think of it why do I like my buicks. I guess I'm a sucker for bastard child designs and even with all the 6.5 short comings I still love my burb. Just like any design short coming someone will come up with a solution. The P400 is the solution. Personally I would just drive it and let it blow up or live the way it is. I've found that if it ain't broke leave it alone is the way to go. Save your money for the replacement that is in your future, whether it's a P400,cummins or dmax swap.

    I Have 230 thousand miles and no blowby and run 14/18 lbs. of boost. She will blow up eventually I'm sure, But all the money I'm spending on parts now are transferable if I go P400 when it does go boom.

    Please don't waste your money on an inferior design that has minimal if any benefit. Ask a reputable engine builder before plunking down any money on that design.

    Anything not tied to the block perimeter is junk, The mains will just flex together, and also overlooked [must be cast iron for same expansion and contraction rate as block!!!] Do the research, this is most important part of any girdle. Just ask my wife. LOL
  9. schiker

    schiker Well-Known Member

    Nov 9, 2008
    Pendleton, SC
    Well just to discuss it a little further .... it could be a combination of the studs (I think the studs are key) and the rails forming a H or I bean type reinforcement. I am always slightly amazed how a truss is so rigid, how adding diagonal members to framing seems to increase rigidity tremendously, and/or bracing a corner post on a fence properly keeps the corner from slowly being pulled to leaning.

    I see the bolts as a cantilever beam with the bolt stretching and adding some stress and strain to the web from thread distortion. I see the stud as more uniformly distributing the thread stresses and the rails as a tie or brace that not really adds torsional strength so much as forms a kinda truss or H /I beam form and lends some extra support to a weak area.

    Again I am not saying its a must have or great band aid or end all product. But I do see some merit for it percieved maybe and I can't really prove it just feel it is better thannothing. Depends on your budget and overall build strategy. I would rather buy a fluid dampener and would do a kit if I had extra $. Or had some cracks and was doing inserts just to add a little more support.
  10. 540s10

    540s10 New Member

    Oct 6, 2009
    perhaps the rails are just a spacer to be able to use cheaper stud kit....
  11. tightgroup

    tightgroup New Member

    Dec 24, 2010
    Well I am starting to reneg my purchase. I have left a deposit and I was suppose to get full ownership today, but I backed out giving me more time to evaluate the true cost of this purchase.. It seems that a cracked block is not an if situation but more of a when situation. From what I have read here on this forum and elsewhere, I should prepare for a block swap very soon. and the right way to go would be with a P400 casting. Now to go long vs drop in is a matter of coins and to some extent piece of mind.

    Looking at that scenario, it means about 10k additional costs on top of the purchase of the Suburban.

    What really erks me is that no one seems to really know why these blocks crack, I would imagine with the millions of 6.5 out there some sort of commonality would of been established. The question is will the P400 suffer the same faith?

    Was it just a question of casting that caused these mishaps, or was it planned obsolescence?? And now we are seeing chinese knock offs;;; what a mess
  12. Turbine Doc

    Turbine Doc Just Another Diesel Guy

    No it's not a when situation, it really is an IF as far as I can see

    I'm running (2) a "at risk" squirter blocks I was told by "experts" I would fail mine by 100K miles, well nearing 220K now with (1) mine lots of power/mods added she's still doing just fine, and 145K with the other one.

    IMO the when factor has more to do with the care & feeding of it while it was operated.

    Multiple theory's on the why they fail; all have some merit, my experience has been that "red-line" for coolant temp, marked at 260F, if you are operating the 6.5 consistently above 210F coolant, & blowing black smoke consistently your when it fails becomes more a true statement, where any mfg defect/design limitation becomes exposed.

    We don't hear often of the ones still running but plenty of "horror stories" on the web of ones that have died, but hey isn't that part of why we post to learn & assist others with their situations.
  13. tightgroup

    tightgroup New Member

    Dec 24, 2010
    Well Turbine Doc,

    The Suburban is now sitting in my driveway :) Again this site is a wealth of information, posted by true passionate 6.5 owners.. Now to get a maintenance plan for this truck.

    Thanks for all the great replies, much appreciated.

    Happy New Year and the very best for 2011 to all members !
  14. EWC

    EWC Active Member

    Jun 14, 2008
    I've got one of the DSG girdle kits for the 97 and up blocks that I'd like to sell . PM if interested .
  15. Turbine Doc

    Turbine Doc Just Another Diesel Guy

    Congratulations or Commiserations only time will tell :) but you have found THE 6.5 Connection on the web should anything go wrong or you need correct info on how to keep it from going wrong.

    When you get a moment go to the user CP button and fill in as much info as you can on the Burb in your signature it will help down the road when/if you have issues, also FYI in the glove box are the RPO codes for how it came equipped option wise from factory.
  16. handcannon

    handcannon Well-Known Member

    Nov 21, 2009
    Albany, OR
    Also, If you go to compnine(dot)com and type in your vin number it will give all the info about date of manufacture, manufacture location, and explanations of most of the RPO codes.


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